Automatic cut-off for gas-burners.



No. 779,006. 0 PATENTED JAN. 3, 1905. H, SMITH.

AUTOMATIC OUT-OFF FOR GAS BURNERS.

APPLICATION FILED 16113.24, 1904 auto-z Patented. January 3, 1905.

PATENT EEicE.

HENRY SMITH, OF NEW YORK, N. Y.

AUTOMATIC CUT-OFF FOR GAS-'BURNEFIS- SPECIFICATION forming part ofLetters Patent No. 779,006, dated January 3, 1905.

Application filed March 24, 1904! Serial No. 199,672.

To aZZ whom, it may concern:

Be it known that I, HENRY SMITH, a citizen of the United States, and aresident of New York, in the county of New York and State of New York,have invented certain new and useful Improvements in Automatic Cut-Offsfor Gas-Burners, of which the following is a specification.

The subject of the present invention is a novel automatic cut-off forgas-burners, and has more particularly in view simple and efficientmeans of the character stated capable of being applied to existingconstructions of fixtures with comparatively little labor and expenseand which will absolutely insure the flow of gas to the burner so longas the flame exists at the tip thereof, but which will positively cutoff the supply of gas to said burner when the flame of the latterbecomes extinguished through causes other than the result of the closingof the gas-cock.

.A development of the invention comprises generally a receptaclecontaining mercury and preferably of glass, which receptacle is adaptedto be so mounted on a burner that while not liable to injury, by theflame its mercury contents will be sensible to the heat radiated fromthe burner, so that the mercury will expand to close a circuitenergizing an electromagnet, the energizing of such magnet serving toexert a slight pull on an armature which has previously been broughtWithin the range of the magnetic field and retained therein by anormally retracted keeper. The armature is connected with the key of thegas-cock, and the latter is so conditioned that it will ordinarily beclosed with the armature out of position. Upon moving the armature tobring it within the range of the magnetic field aforesaid the cock willbe opened to supply gas to the burner, and by then moving thekeeper toengage said armature both the latter will be held against theirretracting tendencies, whereby the cock will thus be maintained open.The energization of the magnet above referred to will initially movesaid armature out of engagement with the keeper, so that the latter willbe retracted out of the way, the armature, however, continuing in theposition corresponding with the open condition of the cock by reason ofthe maintenance of the closed circuit induced by heat generated by theflame at the burner, the gas issuing from which having in the meantimebeen ignited. Should the flame become unintentionally extinguished, theconsequent contraction of the mercury will interrupt the circuit,deenergize the magnet, and permit the normal retracting agency of thearmature to move the same, so as to effect an automatic cut-off of thegas-supply to the burner.

There are other important features connected with my invention, which,besides those alluded to, are clearly explained in the subsequentdetailed description.

In the accompanying drawings, forming part of this specification, Figure1 is a side view of a gas bracket or fixture equipped with one form ofmy invention, the parts being represented in the position they occupyimmediately upon lighting the gas. Fig. 2 is a detail View showing ininverted plan and on a somewhat larger scale the cock portion of thefixture and parts contiguous thereto as exemplifled in the precedingfigure. Fig. 3 is a detail sectional View of the fixture equipped withthe novel cut-off means, the section being in the plane indicated by thebroken line 3 3, Fig. l, but the parts being represented on a largerscale and dotted lines illustrating the position of the armature whenthe cock is closed. Fig. 4: is a detail view illustrating an arrangementwhereby the keeper is adapted to be automatically retracted and held outof position by gravity.

Similar reference characters are employed to designate correspondingparts in the several figures of the drawings.

Considering now Figs. 1 to 3, inclusive, A refers to a gas-cock, whichmay be of the ordinary key-operated ported-plug type and which isinterposed in the fixture or bracket at some point between the burner Band the primary cock (J, which latter is similarin construction andoperation to the cock A. For convenience the cocks A and C will becontiguously located. A torsional spring a embraces the adjacentportions of the casing of the cock A and the key A thereof, one end ofsaid spring being connected with said casing,

while the other end of this spring engages the key, such spring a beingso conditioned that it tends to normally hold the cock in the closedposition. Secured to one side of the key by screws (Z or in any suitablemanner is a vertically flat member D, preferably of brass, which extendshorizontally and has attached at the opposite end thereof theoverlapping portion of a correspondingly-disposed armature D.

In a plane coincident with that of the key A is a pair of transverselyarranged electromagnets E E, the latter being supported by a rigidconnection E with the fixture, the connection illustrated comprising acurved arm secured at one end to the core-bridge e at the rear of themagnets, while the other end carries a divided sleeve 0, adapted tofirmly clamp the fixture by means of a bindingscrew 0 As indicated bydotted circles in Fig. 1, the magnet-poles e e are so positioned thatthe armature D can be moved to bring it within the range of the magneticfield of the magnets E.

On that side of the casing of the cock A corresponding with the side ofthe key A at which the member D is located is attached a plate F, onemanner of attaching which is shown as consisting of a stud f, tappedinto and projecting from the casing side through the plate and havingits outer extremity riveted against said plate. To further insure theproper retention of this plate in position, it has anear f, bent tointimately occupy a depression in the fixture, the secu rement beingfurther augmented, if necessary, by soldering the ear withinthedepression. The plate F likewise has an integral horizontal shank F, tothe outer end of which is pivotally attached a vertically-movable keeperG, desirably of the angular configuration indicated, one member, 9,being that pivotally connected to the shank F, while the other member,g, is curved, so that when the keeper is turned to the positionindicated in Fig. 1 the extremity of the last-mentioned member willfrictionally engage the back of the armature D when the same is inapposition to the magnet-poles and hold the armature in such position. Atorsional spring 9 embraces the shank F of the plate F and has a portiong engaging the keeper G, so as to normally hold the latter out of theplane in which the armature moves.

Attached to the burner-pedestal by any suitable .means as, for instance,a screw-contracted clip his a thermostatic circuit-closer in the form ofa receptacle, preferably of glass and shown as comprising a bulb H,located to be sensible of heat radiated from the upper part of saidburner-pedestal, a vertical tubular leg h of restricted diametercommunicating with and depending from said bulb at the bottom of thelatter, said leg merging in a lower bend, from which continues anextended upwardly-inclining tubular leg 71 corresponding in diameterwith the leg it, the leg k terminating at its upper end in a bulb kconsiderably smaller than the bulb H. A small short leading-in section 6of platinum is fused in and extends through the glass of the bulb H, soas to be in contact with a body of mercury therein. A similar section a"of platinum is correspondingly located in the upper end portion of theleg if, so that one extremity of said section 2" extends with theinterior of said leg. One of the sections, 71, is connected by wire 2'through battery I to the coil-terminal of one of the electromagnets E,while the other section, z, is connected by wire 71 to the coil-terminalof the electromagnet E, thus forming a circuit incomplete at anintermediate point 71. within the leg 7& of the thermostaticcircuit-closer.

From the description thus far it will be readily comprehended that whenthe gas is to be ignited the armature D is moved to bring it intoapposition with the magnet-poles and simultaneously open the cock A.While the armature is so held the keeper G is adjusted so that itsrounded extremity will contact with the back of the armature, with theresult that both the latter and the keeper will be frictionally retainedin the positions stated. The cock O can then be opened and the gasignited at the burner-tip. As soon as the burner-pedestal becomessufiiciently warm to expand the mercury to such extent that it willbring the gap at it in the leg [L2 the electric circuit will becompleted, thereby energizing the magnets E E, so that the armature willbe attracted and held by the same, the slight pull thus induceddestroying the frictional contact between said armature and keeper andpermitting the spring g to retract said keeper out of position.Obviously the armature will be thus maintained with the cock A open aslong as the flame is present; but should said flame be extinguished theresulting contraction of the mercury will again interrupt the circuitand the armature be released, so that the torsional spring a will turnthe key A to close its cock and cut off the flow of gas to the burner.The thermostatic tube is adjusted at such distance from the locale ofthe gasfiame that after the maximum absorption of heat by the mercurythe latter will not rise in theleg A far beyond the point of contactwith the platinum section 2" therein. Moreover, the mercury would notdrop sufliciently to break the circuit when the flame is turned low. Bythis means adjustment to meet different flame conditions can be nicelyprovided for.

Instead of retracting the keeper by a torsional spring the said keepercan be correspondingly operated by gravity. Fig. 4 illustrates onearrangement for accomplishing this result. In said figure the pivotalportion 9 of the keeper G is prolonged beyond the pivotal point andweighted, as indicated at 9 to IOC throw the engaging end of said keeperout of with the armature.

- In constructions where the turning-key occupies an invertedposition-or,in other words, one the reverse to that illustratedtheelectromagnets can be arranged in a coincident horizontal plane, and thekeeper can then be conditioned to drop by its own weight when released.It will also be manifest that the frictional engagement of the keeperwith the armature is of such delicate character that magnets of lowelectromotive force can be utilized, thus admitting of the employment ofa single battery-cell of exceedingly small current force.

The automatic cut-off can, when desired, be rendered inoperative by theinclusion at a suitable point in the circuit of a hand-operatedcircuit-opening device I.

In the event of the improvements being employed in connection withaWelsbach burner the thermostatic circuit-closer can be supported by anarm or bracket on the fixture beneath such burner and supporting themercury- .receptacle, so that the leg it thereof and its bulb H will bewithin the chimney, contiguous to the base of the burner proper.

I do not desire to be understood as limiting myself to the precisearrangement and construction of parts shown and described, but reservethe right to all modifications within the scope of my invention.

Having now described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. In an automatic cut-off for gas-burners, the combination with aburner and a self-closing cock, of an armature movable with said cock,an electromagnet and a normally retracted keeper each adaptedindependently of the other to hold the armature with the cock in an openposition, electric-circuit provision including the magnet-coils, and athermostatic circuit-closer interposed in said circuit and designed forattachment to the burner for location below the plane of the flame zonewhereby said circuit-closer will be sensible more especially to heatradiated from the body of the burner.

2. In an automatic cut-off for gas-burners, the combination with aburner and a self-closing cock, of an armature movable with said cock,an electromagnet and a normally retracted keeper each adaptedindependently of the other to hold the armature with the cock in an openposition, electric-circuit provision including the magnet-coils, and amercury circuit-closer interposed in said circuit and designed forattachment to the burner for location below the plane of the flame zonewhereby said circuitcloser will be sensible more especially to heatradiated from the body of the burner.

3. In an automatic cut-off for gas-burners, the combination with aburner and a normally spring-closed cock, of an armature movable withthe key of said cock, a normally retracted pivoted keeper for engagingthe armature to hold the cock in an open position, an electromagnet,suitable electric-circuit provision connected with the magnet-coils, anda thermostatic circuit-closer interposed in said circuit and in the formof an attachment externally clamped on the burner below the plane of theflame zone, said circuit-closer adapted to be operated to close thecircuit to energize the magnet to release the armature from the keeper,and thereafter hold said armature to maintain the open position of thecock.

Signed at New York, in the county of New York and State of New York,this 10th day of March, A. D. 1904.

HENRY SMITH.

Witnesses:

WILLIAM PAXTON, CHAs. L. WOLF.

